In recent years, a technique for performing high integration of an electronic device using an interposer has attracted attention. For example, as the interposer, a silicon interposer is known which uses a silicon substrate in a core layer.
However, in the silicon interposer, the core layer is configured to have a semiconductor. For this reason, when vias are merely embedded into a through-hole by forming the through-hole in the core layer having the silicon substrate, the vias are short-circuited. Therefore, in the silicon interposer, it is necessary to form an insulating material on an inner wall of the through-hole in order to avoid short-circuit of the vias. Forming the insulating material on the inner wall of the through-hole is an obstructive factor in providing the interposer at low cost.
Therefore, a glass interposer which is the interposer using a glass substrate in the core layer has attracted attention. Since the glass substrate is configured to include an insulator, it is not necessary to form an insulating material on the inner wall of the through-hole. In addition, since the glass substrate is inexpensive compared to the silicon substrate, the glass substrate can contribute to lowered cost of the interposer.
JP 2013-102138A, JP 2012-166999A, JP 2013-537723A, and International Publication No. WO2011/132600 are respectively examples of Patent Reference in the related art.
Examples of the related art include: “3D Silicon & Glass Interposers”, [online], 2012, Yole Developpement, [Jan. 27, 2014 Search], Internet (URL: http://www.i-micronews.com/upload/Rapports/3D_Silicon & Glass_Interposers_sample_2012.pdf); “Cost, Heat Dissipation, and Test: Solution to Three Big Issues of TSV”, Nikkei Electronics, Apr. 16, 2012, p. 42-49; “Has 3 dimensional LSI disappeared?: “Regarding TSV Trends and Manufacturing Technology Innovation”, Nikkei Electronics, Sep. 16, 2013, p. 36-51; John H. Lau, “Evolution, Challenge, and Outlook of TSV (Through-Silicon Via) and 3D IC/Si Integration”, IEEE Japan ICEP, Apr. 13-15, 2011; and Ali Said, et al., “Fabrication of high-aspect ratio, micro-fluidic channels and tunnels using femtosecond laser pulses and chemical etching”, 17 May 2004, Vol. 12, No. 10, Optics Express, p. 2120-2129.
However, in some cases, the glass interposer cannot necessarily obtain sufficiently high production yield since the glass substrate serving as the core layer is damaged during a dicing procedure. In addition, without being limited to the glass interposer, this problem is similarly applied to all of general glasswork components.